Reprogramming towards a germline stem cell fate

项目摘要 生殖细胞的永生是所有有性生殖物种延续的基础。 最近的工作已经确定了生殖细胞和体细胞之间相互转化的频繁例子 命运，暗示可塑性，而不是严格的二分法，生殖细胞和索马之间。在 在成年人中，雄性配子的产生是由生殖系干细胞（GSC）分裂驱动的。在我 在博士后工作中，我建议使用果蝇的强大的易处理系统， 黑腹果蝇雄性生殖系，以确定不朽的生殖系命运的必要因素。此外 到正常的自我更新和分化，GSC可以通过以下方式产生： 精原细胞的脱分化，并可以通过两个强制分化为生殖细胞丢失 细胞和转分化为索马。首先，使用睾丸细胞的单细胞RNA测序， 生殖系正在经历去分化，我将重建谱系过渡， 鉴定从分化细胞（包括生殖系细胞- 自主因素和非自主信令因素。我将同时使用 体内表达表征和基因功能测定。接下来，我将描述 GSC转分化为体细胞所必需的转录变化，鉴定 维持生殖细胞身份的成分。最后，我将利用发现因素 参与a）从分化细胞产生GSC，和B）GSC的丧失 同一性，导致体细胞形成，以开发一种新的模型， 体细胞重编程为生殖细胞的命运。这项工作将大大加深我们对 赋予细胞永生的因素，并将有助于开发治疗方法， 各种人类疾病。

Project Summary Germline cellular immortality underlies the continuation of all sexually reproducing species. Recent work has identified frequent examples of interconversion between germline and somatic fates, suggesting plasticity, rather than a strict dichotomy, between germline and soma. In adults, production of male gametes is driven by germline stem cell (GSC) division. In my postdoctoral work, I propose to use the powerfully tractable system of the Drosophila melanogaster male germline to identify necessary factors of immortal germline fate. In addition to undergoing normal self-renewal and differentiation, GSCs can be generated through dedifferentiation of spermatogonia, and can be lost through both forced differentiation to germ cells and transdifferentiation to soma. First, using single-cell RNA sequencing on testes cells in which the germline is undergoing dedifferentiation, I will reconstruct lineage transitions to identify genes underlying GSC formation from a differentiated cell, including both germline cell- autonomous factors and non-autonomous signaling factors. I will validate these data using both in vivo expression characterization and assays of gene function. Next, I will describe the transcriptional changes necessary for transdifferentiation of GSCs to somatic cells, identifying the components that maintain germline identity. Finally, I will leverage discovery of factors involved in both a) the creation of GSCs from differentiating cells, and b) the loss of GSC identity that results in somatic cell formation, in order to develop a novel model for inducible somatic reprogramming to a germline fate. This work will significantly further our understanding of the factors that confer cellular immortality, and will aid in the development of therapies for diverse human diseases.